You've heard it. Your parents heard it—maybe even your grandparents too. Dentists have been alerting people for more than half a century that high sugar consumption contributes to tooth decay.

That message hasn't changed because the facts behind it are the same in the 2020s as they were in the 1950s: The bacteria that cause tooth decay feast on sugar and other leftover carbohydrates in the mouth. This causes them to multiply and increase their production of acid, which softens and erodes tooth enamel.

What has changed though, especially over the last couple of decades, is a growing understanding of how sugar consumption may affect the rest of the body. Just like the evidence of sugar's relationship to tooth decay, current scientific studies are now showing there are strong links between sugar and diseases like diabetes, heart disease and liver disease.

What's startling about what researchers are finding is that cases of these diseases are growing, Especially in younger people. This is a parallel trend to our skyrocketing increases in per capita sugar consumption: the average American now eats the equivalent of 19.5 teaspoons of added sugar every day. Health experts generally agree we should consume no more than 6 teaspoons a day, and children 4.

This is vastly more than we consumed a generation ago. One reason is because processed food manufacturers have increased sugar in their products, hiding under technical, unfamiliar names in ingredient lists. But it's still sugar, and an estimated 74% of processed foods contain some form of it.

But the real surge in sugar has come from our increasing consumption of sodas, as well as energy and sports beverages. These beverages are high in sugar—you can meet your daily allowance with just one 12-oz can of soda. These beverages are now the leading source of sugar in our diets, and, according to experts, a highly dangerous way to consume it.

In effect, dentists of old were on to something: too much sugar is bad for your teeth. It now turns out that it may be bad for your overall health too. Strictly limiting it in your family's diet could help lower your risk of tooth decay and dangerous diseases like diabetes.